/**
 * Copyright 2004-present, Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.facebook.profilo.core;

import android.os.HandlerThread;
import android.os.Looper;
import javax.annotation.Nullable;

public class TraceControlThreadHolder {

  @Nullable private static TraceControlThreadHolder sInstance;
  @Nullable private HandlerThread mHandlerThread;

  private TraceControlThreadHolder() {}

  private synchronized HandlerThread ensureThreadInitialized() {
    if (mHandlerThread == null) {
      mHandlerThread = new HandlerThread("Prflo:TraceCtl");
      mHandlerThread.start();
    }
    return mHandlerThread;
  }

  public Looper getLooper() {
    return ensureThreadInitialized().getLooper();
  }

  public static synchronized TraceControlThreadHolder getInstance() {
    if (sInstance == null) {
      sInstance = new TraceControlThreadHolder();
    }
    return sInstance;
  }
}
